Many electronic devices receive user input from a keyboard. Traditionally, keyboards include several rows of depressible keys spaced some distance apart. The distance between keys may be selected for aesthetic, functional, structural, dimensional or other reasons. For example, space-constrained electronic devices such as laptop computers may include an integrated keyboard with closely spaced keys.
In some examples, close spacing of keys may heighten user awareness of subtle differences between adjacent keys. For example, color, texture, or height differences may become more apparent the closer individual keys are arranged. Such perceivable differences between keys, especially height differences, may negatively affect the typing experience.
In many cases, the height of a key may be defined by a multi-part mechanical scissor mechanism also used to translate the key downward a selected distance. Conventional scissor mechanisms may include two scissor members coupled to pivot about a midpoint, with a foot portion of one or both of the scissor members able to slide a certain distance during depression of the key. Once the key is released, the foot portion may slide back, returning the key to the upper height. In this manner, the sliding distance of the foot portion may define the height of the key. Accordingly, to ensure uniform height of closely spaced keys having mechanical scissor mechanisms, each scissor member of each key may require exceptionally low manufacturing tolerance, as slight differences in the dimension of the scissor members may translate to perceivable differences in upper height of adjacent keys. In many cases, low manufacturing tolerances may substantially increase the cost of manufacture by increasing rejection rates, material costs, and manufacture time.
Accordingly, there may be a present need for improved mechanical scissor mechanisms for keyboards requiring uniform height of adjacent keys.